The present invention relates to a video signal transmitter and a video signal receiver which may be incorporated, for example, into audio/video (AV) apparatus.
FIG. 4 shows an AV signal transmitter in accordance with the prior art, wherein a dc power-supply (not shown) is connected to dc-power supply input-terminal 54, video-signal 52 is received by video-signal input-terminal 55, and audio-signal 53 is received by audio-signal input-terminal 56.
The video-signal 52 received by video-signal input-terminal 55 is received further by video-signal modulator 57 for modulation, and the signal modulated thereby is then received by electro-optical converter 58 wherein the electrical signal is converted into an optical-signal. Video-signal modulator 57 and electro-optical converter 58 may be defined as video-signal transmitter 38.
On the other hand the audio-signal 53 received by audio-signal input-terminal 56 is received further by audio-signal modulator 39 wherein the audio-signal is modulated. After this, the signal is received by electro-optical converter 40 wherein the electrical signal is converted into an optical signal. Audio-signal modulator 39 and electro-optical converter 40 constitute audio-signal transmitter 41.
The optical signal transmitted from video-signal transmitter 38 is inputted into opto-electrical convertor 42 and is converted into electrical signal which are demodulated by means of video-signal demodulator 43.
Opto-electrical converter 42 and video-signal demodulator 43 may be defined as video-signal receiver 44.
The signal received by video-signal receiver 44 is outputted from video-signal output-terminal 50 through video-signal output-buffer 45.
On the other hand, the audio optical-signal is converted into an electrical signal by means of opto-electrical converter 46, and the electrical signal is demodulated by means of audio-signal demodulator 47. Opto-electrical converter 46 and audio-signal demodulator 47 may be defined as audio-signal receiver 48.
The audio-signal received by audio-signal receiver 48 is outputted from audio-signal output-terminal through audio-signal output-buffer 49.
In a transmit mode, dc-power is supplied to dc-power input-terminal 54, video-signal 52 received by video-signal input terminal 55 is modulated by means of video-signal modulator 57, and the modulated electrical signal is converted into an optical signal by means of electro-optical converter 58.
On the other hand, dc-power is supplied to dc-power input-terminal 54, the optical signal is converted into an electrical signal by means of opto-electrical converter 42, the electrical signal is demodulated into original video signal 52 by means of video-signal demodulator 43, and original video-signal 52 is outputted from video-signal output-terminal 50 through video-signal output buffer 45.
Likewise, for the audio-signal, dc-power is supplied to dc-power input terminal 54, audio-signal 53 received by audio-signal input terminal 56 is modulated by means of audio-signal modulator 39, and the modulated electrical signal is converted into an optical signal by means of electro-optical converter 40.
At the receiver, the optical-signal is converted into an electrical signal by means of opto-electrical converter 46, the electrical signal is demodulated into original audio-signal 53 by means of audio-signal demodulator 47, and the original audio-signal 53 is outputted from audio-signal output-terminal 51 through audio-signal output-buffer 49.
As explained above, in a conventional signal transmitter, video-signal 52 received by video-signal input-terminal 55 when dc-power is supplied to dc-power input-terminal 54, is demodulated into original video-signal 52, and this is outputted from video-signal output-terminal 50.
Likewise, audio-signal 53 inputted into audio-signal input terminal 56 is converted into original audio-signal 53 which is outputted from audio-signal output-terminal 51.